1. Field
The presently disclosed embodiment relates to a speaker including a speaker having a drive mechanism and a passive radiator type speaker, and an edge structure thereof, in particular to an edge having a structure enabling an excessive amplitude of vibration of a diaphragm to be inhibited only with the edge by providing a control part on the edge without using a damper, and to a speaker using the edge.
2. Brief Description of Related Developments
Conventional speakers have, for example, a structure as shown in FIG. 6A. Namely, in FIG. 6A, an outer peripheral end of a diaphragm 2 made of, for example, a cone paper is fixed to an inner peripheral end of an edge 10, an outer peripheral end of which is fixed to a frame 6, and an inner peripheral end of the diaphragm 2 is fixed to an outer circumference of a bobbin 3. A voice coil 4 for flowing a sound current is wound around a bottom end side of an outer circumference of the bobbin 3, and a magnetic field is generated on the voice coil 4 by electromagnetic induction caused by a change in the sound current flowed in the voice coil 4, and by an interaction between the magnetic field and a static magnetic field generated previously by a magnetic circuit 7 comprising a permanent magnet 7a and a yoke 7b, the voice coil 4 and the bobbin 3 are vibrated and then the diaphragm 2 is vibrated, thereby vibrating air to generate a sound. In this case, if an amplitude of the vibration of the bobbin 3 is too large, the amplitude further increases due to an inertia and does not follow the change in the sound current. Therefore, a damper 8 is provided as a control part for controlling the amplitude of the vibration. This damper 8 is connected between the frame 6 and the outer circumference of the bobbin 3, and is configured so that too much movement of the diaphragm in a vertical direction is inhibited. Numeral 5 represents a dust cap.
This damper 8 is produced using a prepreg substrate produced by impregnating a woven fabric made of a cotton yarn, an aramid fiber, or the like with a resin such as a phenolic resin or a melamine resin, and the prepreg substrate is subjected to heating and molding in a mold to be formed into a corrugated shape as shown in FIG. 6A. On the other hand, as shown in an enlarged view of FIG. 6B, the edge 10 is formed into an arc shape and supports the diaphragm 2 to allow it to be easily vibrated freely. The thickness of the edge is uniform and the edge is formed so as to be vibrated freely.